• Membrane Journal
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• v.34 no.1
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• pp.10-19
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• 2024

The bipolar membrane is an ion exchange membrane consisting of a cation exchange layer, an anion exchange layer, and an interface layer, and is a membrane that generates protons and hydroxide ions based on water dissociation characteristics. Using these properties, research is being conducted in various application fields such as the chemical industry, food processing, environmental protection, and energy conversion and storage. This paper investigated the concept of bipolar membrane, water dissociation mechanism, and water dissociation catalyst to provide a comprehensive understanding of bipolar membrane technology, were investigated. Lastly, we also investigated the bipolar membrane process that has been recently applied to energy technology.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.75-78
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• 1998

1. Introduction : The clean technology using ion exchange membranes have drawn attention increasingly with advancement of the membrane synthesis. Ion exchange membranes have been used for diffusion dialysis, electrodialysis, electrodialytic water splitting and electrodeionization. Bipolar membranes(BPM), consisting of a cation exchange layer and an an_ion exchange layer, can convert a salt to an acid and a base without chemical addition. Using the bipolar membrane, a large quantity of industrial wastes containing salts can be reprocessed to generate acids and bases. Recent development of high performance bipolar membranes enables to further expand the potential use of electrodialysis in the chemical industry. The water-splitting mechanism in the bipolar membrane, however, is a controversial subject yet. In this study bipolar membranes were prepared using commercial ion exchange membranes and hydrophilic polymer as a binder to investigate the effects of the interface hydrophilicity on water-splitting efficiency. In addition, the water splitting mechanism by a metal catalyst was discussed.

• Membrane Journal
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• v.11 no.3
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• pp.97-108
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• 2001

Bipolar membranes have gained increasing interest as a tool for an efficient production of acids and bases from the corresponding salts. A large number of potential applications have been identified in the chemical and biochemical industry have been identified and evaluated on a laboratory scale. In spite of extensive research efforts and laboratory and pilot plat test, there are hardly any large-scale commercial plants. In this paper the basic concept of the electrodialytic water dissociation with bipolar membranes are briefly reviewed. The limitations of today\`s bipolar membranes are indicated. Selected examples of successful applications of the bipolar membrane technology are discussed.

• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.630-636
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• 2007

Acidic citrus juices obtained from C. natsudaidai and C. grandis were electrodialyzed with bipolar and organic acid selective membrane (ion exchange membrane) cartridges. The pH levels of the acidic citrus juices gradually increased to 14.5% (C. grandis) and 25.2% (C. natsudaidai) by electrodialysis with the bipolar membranes, while levels remained consistent when organic acid selective membranes were applied. The total acidity levels decreased more with the organic selective membrane than with the bipolar membrane. Conductivity rose with the bipolar membranes while the value continued to fall rapidly with the organic selective membranes. Sugar and flavonoid contents remained relatively unchanged, without any significant differences before and after electrodialysis with each membrane. Also, ion contents were almost unchanged with the bipolar membranes and the electrolyte, $K_2SO_4$, as compared to rapid changes in sodium and potassium levels with the organic selective membranes and the electrolyte, $K_2SO_4$. In summary, the use of bipolar membranes provided juice with better sensory quality than that of the organic acid selective membranes.

• Membrane Journal
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• v.23 no.5
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• pp.319-331
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• 2013

Electrodialysis with bipolar membranes (EDBM) has recently gained increasing attention for the recovery and production of acids or bases from the corresponding salt solutions and other high value-added business like food processing and biochemical industry. EDBM possesses economical and environmental benefits and can complex with other process such as ion exchange process, extraction and adsorption. So this paper investigates a brief overview of development for bipolar membrane and EDBM with the practical application.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.1
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• pp.61-69
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• 2013

Polymer exchange membrane (PEM) fuel cells have multifunctional properties, and bipolar plates are one of the key components in these fuel cells. Generally, a bipolar plate has a gas flow path for hydrogen and oxygen liberated at the anode and cathode, respectively. In this study, the influence of iodine applied to a bipolar plate was investigated. Accordingly, we compared bipolar plates with and without iodine coating, and the performances of these plates were evaluated under operating conditions of $75^{\circ}C$ and 100% relative humidity. The membrane and platinum-carbon layer were affected by the iodine-coated bipolar plate. Bipolar plates coated with iodine and a membrane-electrode assembly (MEA) were investigated by electron probe microanalyzer (EPMA) and energy-dispersive x-ray spectroscopy (EDS) analysis. Polarization curves showed that the performance of a coated bipolar plate is approximately 19% higher than that of a plate without coating. Moreover, electrochemical impedance spectroscopy (EIS) analysis revealed that charge transfer resistance and membrane resistance decreased with the influence of the iodine charge transfer complex for fuel cells on the performance.

• Membrane Journal
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• v.13 no.3
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• pp.143-153
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• 2003

The effects of bipolar interface formed on the surface of cation-exchange membrane on water splitting phenomena were investigated. Results showed that the formation of immobilized bipolar interface resulted in significant water splitting during electrodialysis. In particular, the immobilized bipolar interface was easily created on the cation-exchange membrane surface in the electrodialytic systems where multivalent cations served as an electrolyte. Multivalent cations with low solubility product resulted in violent water splitting because they were easily precipitated on the membrane surface in hydroxide form. Therefore, the bipolar interface consisting of H- and OH-affinity groups were formed on the membrane-solution interface. Apparently, water splitting was largely activated with the help of strong electric fields generated between the metal hydroxide layer and fixed charge groups on the membrane surface. Likewise, the accumulation of large molecular counter ions on the membrane surface led to the formation of a fixed bipolar structure that could cause significant water splitting in the over-limiting current region. Therefore, the prevention of the immobilization of bipolar interface on the membrane surface is very essential in improving the process efficiency in a high-current operation.

• Carbon letters
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• v.14 no.1
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• pp.40-44
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• 2013

The bipolar plate is the most important and most costly component of proton exchange membrane fuel cells. The development of a suitable low density bipolar plate is scientifically and technically challenging due to the need to maintain high electrical conductivity and mechanical properties. Here, bipolar plates were developed from different particle sizes of natural and expanded graphite with phenolic resin as a polymeric matrix. It was observed that the particle size of the reinforcement significantly influences the mechanical and electrical properties of a composite bipolar plate. The composite bipolar plate based on expanded graphite gives the desired mechanical and electrical properties as per the US Department of Energy target, with a bulk density of 1.55 $g.cm^{-3}$ as compared to that of ~1.87 $g.cm^{-3}$ for a composite plate based on natural graphite (NG). Although the bulk density of the expanded-graphite-based composite plate is ~20% less than that of the NG-based plate, the I-V performance of the expanded graphite plate is superior to that of the NG plate as a consequence of the higher conductivity. The expanded graphite plate can thus be used as an electromagnetic interference shielding material.

• Corrosion Science and Technology
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• v.12 no.4
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• pp.171-178
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• 2013

In a polymer membrane fuel cell stack, the bipolar plate is a key element because it accounts for over 50% of total costs of the stack. In order to lower the cost of bipolar plates, 316L stainless steels coated with nitrides such as TiN and CrN by physical vapor deposition were investigated as alternative materials for the replacement of traditional brittle graphite bipolar-plates. For this purpose, interfacial contact resistances were measured and electrochemical corrosion tests were conducted. The results showed that although both TiN and CrN coatings decreased the interfacial contact resistances to less than $10m{\Omega}{\cdot}cm^2$, they did not significantly improve the corrosion resistance in simulated polymer electrolyte membrane fuel cell environments. A CrN coating on 316L stainless steel showed better corrosion resistance than a TiN coating did, indicating the possibility of using modified CrN coated metallic bipolar plates to replace graphite bipolar plates.

• Membrane Journal
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• v.32 no.5
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• pp.357-365
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• 2022

Recently, as the demand for secondary batteries for electric vehicles has rapidly increased, the efficient production of lithium compounds is attracting great attention. Bipolar membrane electrodialysis (BPED) is known as an eco-friendly, economical, and efficient electrochemical lithium compound production process. Since the efficiency of the BPED depends on the performance of the bipolar membrane (BPM), the selection of the BPM is very important. In this study, the characteristics of BPMs suitable for the BPED for electrochemical LiOH production were derived by comparative analyses of BP-1E (Astom) and FBM (Fumatech), which are the most widely used commercial BPMs in the world. Through systematical evaluation, it was confirmed that reducing membrane ion transfer resistance and co-ion leakage among the characteristics of BPM is the most important, and BP-1E has better performance than FBM in this respect.